Placer-dredge tumbler.



W; G. NICHOLS.

PLACER DREDGE TUMBLER.

APPLICATION FILED car. 2. ms.

Patented J we 12, 1917.

WESLEY GEOFF NICHOLS, OF, CHICAGO HEIGHTS, ILLINOIS, ASSIGNOR TO AMERICAN MANGANESE STEEL COMPANY, OF- CHICAQO, ILLINOIS, A CORPORATION OF MAINE.

subsequent treatment.

rnacnnnnnnen TUMBLEE.

Specification of Letters Patent.

Patented June 12, 191?.

and useful Improvements in Placei-Dredge Tumblers, of which the following is a specification.

In dredges the dredging is usually done by a chain of buckets fastened together in a suitable manner and adapted to move over a boom or leg. These buckets weigh two to four thousand pounds apiece and, as a chain is sometimes composed of as many as eighty of these buckets, there results a very cumbersome and heavy conveyer.

The boom or leg is provided with rollers or tumblers, one at each end of the boom, over which the chain of buckets moves. The top tumbler is positively driven which imparts motion to the chain. The lower tumbler is freely revoluble and is mounted on the bottom of the boom. These rollers weigh from nine hundred to twenty-six thousand" pounds apiece, so that the matter of breakage and consequent delay therefrom is of vital importance. Heretofore the lower tumblers have been made from a single casting and are substantially spool-shaped withproper flanges for guiding the chain of buckets. It sometimes happens in dredging that rocks, etc., are struck by some of the buckets on the chain thereby causing a sharp sidewise movement of the'chain, which results in the breaking of one of the flanges of .the tumbler. Oftentimes the flanges wear ofl' and it is necessary to stop the operation of the dredge until a new casting can be secured.

One of the largest items of expense'in the casting of manganese steel is the loss from faulty castings, either in the mold or in Furthermore, such castings may have defects not apparent to the eye which may result in failure in service with consequent loss to the manufacturer by whom it must be replaced. An object in,

the present construction is to reduce the liability to the production of faulty castings by so desigmng the parts that shrinkage strains are reduced, this result being secured partially by forming the usually huge casting in two portionsth e outer or flange portion, and a hub or drum portion, the drum p rtion adapted to fit ithin the flange portion with provisions for holding the parts from disengagement. As it is necessary to make the connection water-tight I prefer to shrink the flange portion onto the drum portion, thus. removing all chance of separation. If the flange member of my improvedtumbler be broken or worn out, it is necessary to replace same by cutting oil? the flange member of the drum withthe aid of oxyacetylene flame, or somaother cutting means, and to shrink on a new flange member. It will readily be seen that the drum can be used indefinitely and refitted many times with spool membersa construction which will'greatly reduce the time consumed in breakage and will reduce the cost of repairs, I prefer to make thespool and drum members from manganese steel, thereby furnishing a tumbler oflering the greatest resistance towear and breakage. I also prefer to form the drum member with imperforate ends having its. interior cored out, as I secure a lighter casting without sacrificing strength.

Further advantages will be seen by referring tothe drawings wherein:

Figure 1 is an end view of a tumbler embodying my invention, showing a drum member in place and the flange member.

Fig.2 ,is a section on the line 2-2 of Fig. 1.

Fig. 3 is a section on the line of V ber having the usual recess for. a chain and provided with a central aperture; 11

represents thedrum member formed with imperforate ends and having slots 12 in its surface. An aperture .13 is providedin the drum 11 for, the reception of the shaft on which the tumbler is mounted. Extending part way inwardly from the ends of the drum 11 are sleeves 14' formed for the purpose of providing greater bearlng surface on the shaft (not shown). which extends through the tumbler. LongitudinaZlly-extending ribs 15 are formed within the drum for the purpose of strengthening the surface of the drum and also for supporting the. sleeve members 14. In order to secure the drum against endwise and rotative movement when put in the flange member 10, I pro ide on t 9 interior of the flange mem er wise movement by engagement of the lugs 16 with the enlarged end portions of the keyway. I provide fillers 19 to close the keyways 17 after the drum is in place. Before the joining ofthe drum in the flange I heat the flange member to expand it in order that it'may. shrink onto the drum. .1 thus make a water-tight connection all the-way around. This shrinking also prevents any endwise or rotatlve movement of the drum' and is suflicient for the prevention of such movement, although- I prefer to employ the lugs 16 ahd the keyway 17 as described.

I do not confine myself to the precise form shown, but consider the form admissible of modifications,- and such modifications as come within the scope of my claims I.con-

sider as being within the spirit of my invention.

I claim:- 1. A dredge tumbler of relatively great size and weight, comprising, in combination,"

a spool and a drum, said drum being constructed inthe form of a skeleton cylinder,

the peripheral surface of which -is interrupted by spaces, said drum and s'pool'having interen'gaginglugs and recesses, and a key for positively locking said parts againstrelative movement, substantially as described.

2. In a dredge tumbler, the combination of a hollow cylindrical shell having an axial sleeve providing a shaftopening, the peripheral surfacerof the cylinder being interrupted by a series of spaces, the shell being ,said spool is adapted to be provided with keyways on its surface, and a spool having an; axial opening and provided with lugs projecting into said opening, said lugs being adapted to engage with said keyways, and means for permanently securing said spool and drum in engagement. v n I 3. In combination, a spool and a drum,

said drum being cylindrical in shape and provided with a central aperture therey the drum slidably engaging with said spool,

in its periphery, and a cored interior por-y tion, the" surface between said slots being provided with keyways having enlarged ends, said spool being provided with a cylindrical central aperture, and with lugs on the surface thereof engaging with said key- Way in said drum, substantially asdescribed. 4. A dredge tumbler of relatively great size and the principal component parts of which are composed of alloy steel, comprising in combination a one-piece spool and a one-piece skeleton drum upon which said spool-is adapted to beQperman'entIy. mounted, the wall composing the spool being of substantially uniform thickness at all points, said drum having an axial hub which is interrupted at a point intermediate its ends,

and means for permanently uniting said drum and spool, substantially as described.

5. A drum,'a spool mounted thereon, said spool having an aperture and being provided withlugs, said drum beingprovided with keyways engaging with said lugs and interlocking therewith, said drum having an axial shaft opening and provided with otherwise-Iimperforate ends and a skeleton bodyand 'slidablyinsertible in said spool, sub

stantially as described.

6. A dredge tumbler of relatively great size and weight andtheprincipal componentparts of which are composed of alloy steel, comprising in combination a one-piece spool and a one-pieceskeleton drum upon which said spool is adapted to be permaw nently 'mounted,othe walls composing the spool and drum being of substantially uniform thickness at all points, said spool being shrunk ontosaid drum in order to permanently unite the parts, substantially as described. I

7. A dredge tumbler of relatively great size and weight, comprising in combination a one-piece spool composed of alloy steel and a one-piece. skeleton drum uponv which 'ermanently mounted, the walls composing t e spool being of substantially uniform thickness at all points, whereby shrinkage strains are avoided in the casting of the article, said spool being shrunk onto said drum, said drum and spool having interengaging lugs and recesses for positively preventing rela tive rotation of said spool and drum, sub-- stantially as described.

- WESLEY GEOFF NICHOLS.

Witnesses O. W. KCARLSON,

CHARLES PAMs'rRoN. 

